Plunger-switch mechanism



Dec. 14 1926.

L.l MEUNIER PLUNGER SWITCH MECHANI SM Filed July 17, 1925 /VVENTR leon Meuh/'er BY/s ATT Patented Dec. 14, 1926. y

UNlTED STATES l LEON MEUNER, OF CLEVELAND, OHIO, ASSIGNOR TO CV CAGO PNEUMATIC TOOL COM- PANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

PLUNG-ER-SWITCH MECHANISM.

Application filed July 17, 1925.

rl`his invention relates to electrical control devices or switches and is ol general applica tion although designed and intended for use on hand V'to ls, it particularljyf concerns switches uJv ing a rotary bloeit engaged by s and has special reference to oiE the plunger device which ets ion oi the switch block.

ln switches ot the type described the push lo member or plunger' carries a pivoted pawl shoulders or teeth on the -teh bleu. -o rotate the latter. The shoulfler or toe-th on the blocl; rocks the pawl on pivot as.' 'inst the tension ot a spring as ie block i turno-d to its new position and the r is retracted. The spring for res" -ie pawl to o1 erative position, as heretofore used, has been ot round or 'liat spring material with a single straight or slightly bent section which had to resist the movements ot the pawl. The frequent lier ing' ot this section ot the spring produced by the stopping and starting oit a portable tool soon results in Yfatigue ot the metal ot the spring' and breakage, whereupon the manual control device :tor the switch becomes inoperative.

Among the objects oit the invention are to prevent failure of switches ot the type de- ?0 scribed, to provide a switch structure in which breakage strains on the sprii is argely it not entirely eliminated, and in general to improve prior devices of the class `described in the interests ot more ei'iieient and satisfactory service.

In order to illustrate the invention one concrete yembodiment thereof is shown in the accompanying drawings, in which:

Fig. 1 is a side elevational view showing fri the tool casing` broken away.

Fig. 2 is fragmentary ver'ieal sectional view substantially on the line 2--2 oi' Fig. 3 but showing` the plunger depressed.

Fig. 3 is a t 'ansverse sectional view subtialliT on the line ot Fig. l.

The invention is illustrated as embodied in the manual control handle A for a portable electric tool ot which a portion ot the casing B tiereot is indicated in Fig. l. The

afl control switch mechanism is mounted in the grip portion A ot' Handle A which is hollow for this purpose and has a removable cover plate a secured in place by screws u. The switch mechanism comprises the block il, mounted 'for rotation on apivot 4L sup- Serial No. 44,198.

, the power tor opeived through a Suitable means are provided tor stepping block around in order to operate ltool rlhe means on block l tor this purpos will.

.zy comprise a )Leu i schot ieel il presenting A or shoulders ile i sockets to be engaged in accordance s'. '.l A Ynotice by pawl member 8. 'lhe improved means by which this pawl member 8 is retracted t operative position hei: ".ced l one ot the ratchet teeth le and constitutin the present invention will noi be d l eo.. Fawl 8 is pivoted at in, citen ori fard end of a manually operable plunger' l0 mounted for sliding movement in a differential bore a2 in the upper end ot grip A. A coiled spring 11 seated in the forward end of the large bore and engaging a shoulder on plunger l0 normally urges the latter' to the position shown in Figs. 1 and 3. Plunger 10 has a central bore 1,2 terminating` adjacent its bifurcated end within which is slidably mounted a cup shaped abutment member 13 backed by a coiled spring lev retained iu plunger il) by screw glug l5 closing the outer end of bore 12. Abutment member 13 has a plane tace engaging a straight edge 8 on pawl 8 normally disposed transverse to the anis of plunger l0, so that in the retracted position et plunger 1 0 (Fig. l) pawl 8 is disposed substantially in line with plunger lO to engage one of the teeth #le oit ratchet' wheel Lid.

The operation ot' the switch mechanism will be apparent from Figs. l and 2. With th-e parts in the position shown in Fig. l pressure on the plunger 10 by the thumb of the operator forces the plunger inwardly against the pressure ot spring 11. Pawl S as it advances forces block 4; to rotate in a countercloclrwise direction. As block 4 in its rotation snaps into its next position the following tooth fie engages pawl 8 and rocks it on its pivot 9 to the position indicated in Fig. 2 wherein abutment 13 is displaced rearwardly against its coiled spring 14. As the operator releases plunger 10, spring 1l restores it to its former position (Fig. l) and pawl 8 is drawn rearwardly of the tooth le and on clearing the same, the spring pressed abutment- 13 restores pawl 8 in an obvious manner again to operative position as shown in Fig. l

From the above it will be apparent that theV improved switchl mechanism herein disclosed largely eliminates, if not entirely avoids, the chance of failure in switch mechanism of the type described through breakage of springs in the manual controlstructure, by reason of the use of coiled springs which are not subjected to acute iiexes and strains, and it is to be understood that the invention is not confined to the specific details herein disclosed but covers all changes, adaptations and modifications within the scope of the appended claims.

I claim as my invention:

1. In an electrical control device having a rotatable switch block provided with circumferentially spaced sockets, a plunger for rotating said block having a pivoted pawl for engagement in said sockets, and means movable axially within said plunger for maintaining said pawl in operative'position but permitting rocking movement on its pivot in response to rotation of said block effected by said plunger. f

2. In an, electrical control device having a rotatable switch block provided with circumferentially spaced sockets, a plunger for rotating said block having a pivoted'pawl for engagement in said sockets, said plunger having a bore rearwardly of said pawl, and a yielding abutment member for said pawl slidable within said bore arranged to be forced rearwardly as the plunger is advanced to rotate said block, said rearward movement of said abutment permitting rocking movement of .said pawl.

3. In an electric switch having a rotatable switch block provided with circumferentially spaced sockets, manual control means therefor comprising al spring pressed plunger, a pawl pivoted adjacent the forward extremity of said plunger and presenting a rearward face transverse to the axis of said plunger, a spring pressed abutment movable axially within said plunger and presenting a fiat face for engagement with the transverse face of said pawl, said abutment being forced rearwardly by the rocking of said pawl upon its pivot as the plunger is advanced to cause the pawl to rotate said block.

a. In an electric switch having' a rotat4 able switch block provided with circumferentially spaced sockets, manual control means therefor comprising a spring pressed plunger, a pawl pivoted adjacent the for-A wardA extremity of said plunger and presenting a rearward face transverse to the axis of said plunger, said plunger having a bore rearwardly of said pawl, an abutment slidable in said bore and presentingatlat face to engage said transverse face et said pawl, and a compression spring in said bore engaging said abutment, said abutment being forced rearwardly by the rocking movement of said pawl upon its pivot as the plunger is advanced to cause the pawl to rotate said block.

5. In an electric switch having a rotatable switch block provided with circumferentially spaced sockets, `manual. control means therefor comprising a s ring pressed plunger, a pawl pivoted adjacent the ferward extremity of said plunger and presenting a rearwardl face transverse to the axis of said plunger, said plunger having a longitudinal bore therein, terminating rearwardly of said pivot, a cup shaped member slidable in said bore and presenting a face for engagement with said face of said pawl, a plug clcsing the rearward end of said bore. and a coiled spring interposed between said plug and said member and extending within the latter for maintaining said member and said pawl in engagement.

6. Ina handle attachment for portable electrical tools having a grip portion, a switch within said portion comprising a rotatable block and yielding contacts engaging opposite faces thereof, manual means for stepping' said block around comprisingl a spring pressed plunger projectino' from a bore in the upper part of said. grip portion, a pawl pivoted on the outer end of said plunger for engagement with ratchet teeth on said block,y an abutment member slidably mounted in a bore in said plunger to engage said pawl rearwardly of its pivot, and a coiled spring engaging said member within said bore, said member being forced rearwardly in said bore by the rocking movement of said pawl on its pivot as the plunger is advanced to produce rotation of said block by said pawl. v

Signed by me at Cleveland this 8th dav of July 1925. I

LEON MEUNIER.

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